Work holding device



Dec. 29, 1964 Filed Oct. 2, 1962 L. Ross 3,163,433 WORK HOLDING DEVICE 2 Sheets-Sheet 1 F2121, 25A 24 2s 1* 4 23 24 I 5 ,A-w

INVENTOR. Louis Ross AT TO RNEY wdRx HOLDING DEVICE Filed Oct. 2, 1962 2 Sheets-Sheet 2 FIG.4

INVENTOR.

Louis Ross yw ww AT TORNEY 3,163,433 W ORK HOLDlNG DEVICE Louis Ross, New York, N.Y., assignor to Helen Ross, New York, N.Y. Filed Get. 2, 1962, Ser. No. 227,916 7 Claims. (CL 279--46) This invention relates in general to a work holding device, and more specifically to a diaphragm type work holder especially adapted for the machining of precision parts.

Heretofore, diaphragm type work holders comprised relatively complicated and expensive structures. For this reason it was not economically feasible for relatively small machine shops to purchase the same. Also the known type diaphragm work holding devices did not generally consist of a self-contained unit. That is the known diaphragm type holding devices required an external pneumatic or hydraulic source of pressure to operate the same. Also a further disadvantage of the known diaphragm chuck constructions is that the jaw members of such chucks cannot be closed onto the work piece with the same amount of holding force upon each closing thereof. This was because holding force applied was generally dependent upon the skill and experience of the individual machinist.

Therefore, an object of this invention is to provide a diaphragm type work holder which comprises an entirely self contained hand operated unit that is relatively simple in construction and operation.

Another object is to provide a more versatile dia-j phragm work holder which can be readily adapted for holding a work piece of any desired shape.

Still another object is to provide a diaphragm type work holder that is readily adapted for use with solid spindle machines as well as with others.

Still another object is to provide a diaphragm type holding device in which a uniform holding force is exerted upon each closing of the device independent of any operator skill.

In accordance with this invention the foregoing objects, and other features and advantages are attained by a work holding device comprising essentially a base plate, a mounting plate connected in spaced relationship therewith, and a diaphragm member connected to the mounting plate. Fixed to the diaphragm are a plurality of fixed jaws which are adapted to open and close upon the flexing of the diaphragm. Means in the nature of a screw jack with a ball fulcrum are utilized to flex the diaphragm upon the rotation of the screw jack accordingly. Means are operatively associated with the screw jack so as to assure that a uniform force is applied on each closing of the device. Also, provisions are made for leveling a work piece thereon in the event a smooth, flat or finishing operation is required thereon.

A feature of this invention resides in the provision that the diaphragm holding device is relatively simple in corn struction, relatively inexpensive to fabricate and positive in operation.

Another feature resides in the provision of means for leveling a work piece on said holding device if such is desired.

Other features. and advantages will become more read ily apparent when considered in view of the drawings and specifications in which:

FIG. 1 is a vertical sectional view of the holding line 11 of FIG. 2, the device being illustrated in work holding position.

FIG. 2 is a plan view of FIG. 1, having a portion thereof broken away.

United States Patent FIG. 3 is a partial vertical sectional view similar to that of FIG. 1, but illustrating the device in open position.

FIG. 4 is a detail plan view of the flexible diaphragm.

FIG. 5 is a detail plan view of the actuating ring.

Referring to the drawings there is disclosed the work holding device of this invention. The device 10 comprises a base plate 11 which is adapted to be fixed either to a machine spindle 12 or it may be fixed to a bed of a machine. Connected to the base plate 11 is a mounting plate 13, the respective plates 11 and 13 being. maintained in spaced relationship by spacer bushings or sleeves 14 and fastener means 15, such as Allen head screws. As shown in FIG. 2, the spacer sleeves 14 and fastening means 15 are equidistantly spaced about the circumference of the plates 11 and 13. In the illustrated embodiment fasteners 15 are spaced 120 apart.

A threaded opening 16 is located centrally of the mount ing plate 13. If desired, the mounting plate 13 may be provided with a plurality of tapped holes 17 for receiving back stops 18, as will be hereinafter set forth.

Connected to the mounting plate 13 is a flexible diaphragm 19 which is preferably formed of a steel plate or the like. In the illustrated embodiment as seen in FIG. 5, the diaphragm 19 includes a hub portion 19A having a plurality of spider arms 19B extending radially outwardly therefrom. Connected integrally with the ends of the spider arms 19B is a circumscribing mounting ring portion 19C. As shown, the diaphragm 19 is slightly spaced from the mounting plate 13 by washers 20, and fastener means 21 and 15 circumferentially spaced about ring portion 19C serve to secure the diaphragm 19 to the mounting plate 13. It will be observed that the fasteners 21, securing the diaphragm 19 to the mounting plate 13,

are rotated 60 with respect to the fasteners 15 which ex-v tend through the diaphragm and both plates 11 and 13.

A plurality of jaw or gripping members 23 are connected to the diaphragm. Accordingly, each of the diaphragm spider arms 19B is provided with several spaced, tapped holes 22. The jaw members 23 are thus secured by a fastener 24 which is extended therethrough and threaded into one of the tapped holes 22. It will he therefore apparent that the respective jaw members 23 may be adjustably disposed along the spider arms 19B to accommodate a given size work piece 25.

In the illustrated embodiment the jaw members 23 are depicted as hexagonal blocks. However, it will be understood that the jaw members 23 may assume any desired shape. To accommodate a given work piece 25, the ends of the respective jaw members 23 are machined to the tolerance of the work piece 25. As shown in FIGS. 1 and 2, each jaw member 23 is machined to define a seat or recessed portion 25 conforming substantially to the shape of the work piece so that the latter may be received therein when the jaws are opened, as in FIG. 3.

In accordance with this invention a screw jack 27 is threaded in opening 16 of the mounting plate 13. As shown in FIG. 3, the upper end of the screw jack 27 is provided with a recess 28 in which a ball 29 is seated.

Accordingly, the ball 29 is wedged between the hub 19A of the diaphragm 19 and the screw jack 27. Thus as the screw jack 27 is rotated toward the diaphragm 19, the ball 29 is vertically displaced, causing the diaphragm to be forced or bowed outwardly, as seen in FIG. 3. 'When this occurs the jaw members 23 are displaced outwardly to thereby release the work piece 25. When the screw jack 27 is backed off, the inherent resiliency of the diaphragm 19 causes it to assume its natural flat state, thus causing the jaw members 23 to close onto the work piece 25 positioned in the machined seat 26 thereof, as seen in FIG. 1.

Means are provided to facilitate actuation of screw 7 jack 27. As shown this means comprises an actuating ring 30 circumscribing the "circumference of base plate 1 11, and a connector 31 connects the ring 30 to the screw jack 27 so that rotation of the ring effects rotation of thescrew jack 27 accordingly. In the illustrated embodiment the connector 31 comprises a triangular plate, the corner or angles 31A of which are welded'or otherwisesecured to the inner circumference of actuator ring 30. In accordance with this invention the arrangement 'of the actuating ring 30 is such that the corners 31A of the connector plate 31 are'rextended beyond and dis- 15 seeuring'the plates 11 and 13 together. Thus it will be apparent that the limit of rotation of the ring 30in either direction is approximately 6 since the spacers 14 function as limitstops for the ring 30.

From the foregoing description it will'be apparent that the screw jack 27 can be axially advanced only a limitedamount, which amount is predetermined by the specific'threaded design of the screw jack 27, the relaposed midway between adjacent spacers 14 and fastener I tive spacing between adjacent fasteners 15, which limit a the angular rotation of the actuating ring 30, and the tolerance between the work piece and the seat 26 machined in jaw members 23xadapted to grip the same. Thus for a givenholding device 10 and a given work piece 25, the amount of holding force exerted on the work piece 25 is always uniform and independent of any ,operator skill or experience. Y

If leveling of a work piece having a hub 25 and a flange 25A is'required, a series of threaded back stop pins 18 may be arrayed beneath the work piece flange 25A and threaded into theitapped hole 17 located in the mounting plate 13 between the spider arms 19B 'of' the diaphragm 19; Through the appropriate adjustment of the respective back stop pins 18, the work piece hub 25 will be supported in the jaws 23 while being banked against the pins 18-to achieve the degree of leveling desired or necessary.

few number of parts, and which devic'eis easy ,to operate. It is versatile in that it canbe readily adapted to any machine operation. The device 10 is specifically constructed to exert a uniform force upon each closing thereof. Also the device can'be manufactured and sold at a relatively small cost, thereby rendering it readily. available to the smaller shops which'could ill afiord the more complex and relatively expensive holding devices of the typerheretofo're known. 7

While the instant invention has been disclosed with reference to. a particular embodiment, it is to be appreciated that the invention is not to; be taken as limited to all of the details thereof as modifications and variations From the foregoing description it 'willbe apparent that the 'work holding device 10. of this invention is relatively simple in structural arrangement having a relatively (a diaphragm flexing screw means operatively dis- 7 posed perpendicularly between said plate andsaid.

diaphragm; and selectivelymovable toward and away I from said diaphragm along a predetermined axis to effect and to maintain varying degreesoftfiexion therein, (d) actuating means flexing, means and' projecting perpendicularly from said axis, and adapted for rotation thereabout,

V pattern on 'said'diaphragm -and being co'ntrollably selectively. expandable and retractable,respectively,

l "with the variable flexi'on' of" said diaphragm 'away fiom and toward said mounting plateassociated. with said diaphragm I 1(2). a plurality 'of'jaws arrayed in a; predetermmed 2. The-chuck of claim 1, in which (a) said jaws comprise. a seriesof block means, a a (b) said block means being adapted to be machined to define a seat for a workpiece. 3. A self-contained diaphragm chuck comprising (a) a base mounting plate, I Y (b) a flexible diaphragm fixedly mounted substantially parallel with and spaced from said mounting plate, 7 (c) a screw jack means operatively disposed perpendicularly of said plate and said diaphragm, (d) fulcrum means carried by said screw jack means and selectively movable toward and away from said diaphragm along a predetermined axis to effect and i to maintain varying degrees of flexion therein,

(e) actuatingmeans associated with said screw jack means and projecting radially outward from said axis, and rotatable thereabout,

I (f) a plurality of jaws arrayed in a predeterminedpattern aboutsaid diaphragm and being variably selectively expandable and-contractable, respectively, with the variable fllexion of said diaphragm away from and toward said mounting plate.

4. A self-contained diaphragm chuck, comprising (a) a'basemountingplate, g

(b a flexible diaphragm fixedly mounted substantially parallel with and spaced from said mounting plate,

(0) a screw jackmeans'operatively disposed between said plateand'said diaphragm, 1

(d); fulcrum means carried by said screw jack means and selectively movable toward and away from said diaphragm along a predetermined axis to effect and to maintain varying degrees of flexion therein,

(e) actuating means associated with said screw jack means and projecting radially outward from said axis,

pattern about said diaphragm and being variably selectively expandable andcontractible, respectively, with the variable flexion of said diaphragm away fromand toward said mounting plate,

v (,g) a plurality ofposts supporting said diaphragm screw jack means to predetermined amounts which 7 are a function of the mutual spacing. of said posts. 5. AseIf-c'ontained diaphragm chuck comprising (a) a base mounting plate, I

(b) a flexible diaphragm fixedly mounted substantiala ly parallel with and spaced from said mounting plate,

' c) 'said diaphragm includes a substantially circular central portion,

(d) a screw jack means operatively disposed between said plate and said diaphragm, r (e) substantially sphericalfulcrum means carried by said screw jack means and selectively movable to ward and away from'said diaphragm along a pre determined axis to effect and to maintain varying degreesof fiexion therein, I i

fmeans and projecting radially outward from said axrs, i

(g) a plurality of jaws arrayed in a predetermined.

pattern'about said diaphragm and being variably se 'lectively expandable and contractible, respectively, 7

6. A self-contained chuck'in accordance with claim 5,

in which (f) a plurality of jaws arrayed in a predetermined (f) actuating means associatedlwith said screw jack,

(a) 'saidbas e plate is substantially circular and has a diameter substantially equal to that of the dia p (b) said actuating means includes a cylindrical sleeve which is concentric with said base plate and said diaphragm and surrounds the circumferential portions of said base plate and said diaphragm.

7. A self-contained diaphragm chuck comprising (a) a base mounting plate,

(b) a flexible diaphragm fixedly mounted substantially parallel with and spaced from said mounting plate,

(0) a screw jack means operatively disposed between said plate and said diaphragm,

(d) fulcrum means carried by said screw jack means and selectively movable toward and away from said diaphragm along a predetermined axis to eiTect and to maintain varying degrees of fiexion therein,

(e) actuating means associated with said screw jack means and projecting radially outward from said axis,

(f) a plurality of jaws arrayed in a predetermined pattern about said diaphragm and being variably selectively expandable and oontractible, respectively, with the variable fiexion of said diaphragm away from and toward said mounting plate,

(g) said jaws comprise a series of hexagonal blocks,

(h) said blocks being adapted to be machined to define a seat for a work piece.

References Cited in the file of this patent UNITED STATES PATENTS 1,938,356 Searles Dec. 5, 1933 2,331,111 Dunn Dec. 5, 1943 2,524,006 Capellazzi Sept. 26, 1950 2,912,892 Hoern Nov. 17, 1959 

1. A SELF-CONTAINED DIAPHRAGM CHUCK COMPRISING (A) A BASE MOUNTING PLATE, (B) A FLEXIBLE DIAPHRAGM FIXEDLY MOUNTED SUBSTANTIALLY PARALLEL WITH AND SPACED FROM SAID MOUNTING PLATE, (C) DIAPHRAGM FLEXING SCREW MEANS OPERATIVELY DISPOSED PERPENDICULARLY BETWEEN SAID PLATE AND SAID DIAPHRAGM AND SELECTIVELY MOVABLE TOWARD AND AWAY FROM SAID DIAPHRAGM ALONG A PREDETERMINED AXIS TO EFFECT AND TO MAINTAIN VARYING DEGREES OF FLEXION THEREIN, (D) ACTUATING MEANS ASSOCIATED WITH SAID DIAPHRAGM FLEXING MEANS AND PROJECTING PERPENDICULARLY FROM SAID AXIS, AND ADAPTED FOR ROTATION THEREABOUT, (E) A PLURALITY OF JAWS ARRAYED IN A PREDETERMINED PATTERN ON SAID DIAPHRAGM AND BEING CONTROLLABLY SELECTIVELY EXPANDABLE AND RETRACTABLE, RESPECTIVELY, WITH THE VARIABLE FLEXION OF SAID DIAPHRAGM AWAY FROM AND TOWARD SAID MOUNTING PLATE. 